'By the time I found out about my risk, I probably had cancer already.' Photograph: Alamy

In 2003, 20 years after my aunt died of ovarian cancer, I found myself sitting in a consulting room with two young doctors. "I'm afraid it's bad news," said one. "You're positive."

A blood test had shown that I was carrying the BRCA2 mutation, which meant I had an 80% chance of getting breast or ovarian cancer at some point in my life. I'd inherited the gene from my father who, unlike his sister, never showed any outward sign of carrying it. I was told to consider having my perfectly healthy breasts and ovaries removed. It seemed ridiculous.

I turned to my cousins for advice, both of whom had already had breast cancer. "Have the ovaries out, because ovarian cancer killed our mother," they said. "It is more difficult to detect and much more difficult to survive. But leave the breasts. We survived breast cancer and you can too."

Their words were prophetic. One month after I'd had my ovaries removed, in October 2003, I found a malignant lump. In January 2004, I went ahead with the mastectomy and chemotherapy, and had no doubt what to do next. "I want to have my second breast removed," I told the doctor. "I don't want to take any more risks."

Gaby Koppel … 'I turned to my cousins for advice.'

So, in September 2004, I went back to hospital to have a second mastectomy. I felt nothing but relief after the operation, but when it came to reconstruction there was something of a nasty surprise. It wasn't exactly Hollywood style. The specialist nurses showed me an album of real life patients – unappealing surgical photographs of strangely shaped breasts made of a patchwork of different skin colours, with unnatural looking nipples.

I decided against the nine-hour surgery, which would move bits of my back to my front with uncertain results. I opted for minimal reconstruction instead: simple implants placed under the muscles of the chest wall. As a result, I am criss-crossed with scars and have no nipples. Without clothes I must look decidedly odd, but when I'm dressed I look normal (I think) and decided to concentrate on staying a fit and healthy size 10, instead of worrying too much about whether my lack of decolletage robs me of my femininity.

Now, at 56, I do regret not having the double mastectomy earlier, but the truth is that, by the time I found out about my risk, I probably had cancer already. I'm happy just to be alive and healthy.

The most painful part of the process is knowing that I may have passed on the faulty gene to my own family. I only found out that I was carrying BRCA2 after I'd had three healthy children. My girls, aged 21 and 17, grow up facing difficult decisions about whether to be tested, and then about surgical options. My 14-year-old son may also have an increased risk of certain cancers. All I can do is stand by with advice and comfort while we all hope that medical advances will make the decisions that they have to make easier in the future.